Sökning: "Effective spin models"

Hittade 4 uppsatser innehållade orden Effective spin models.

1. 1. Error propagation in nuclear models

   Kandidat-uppsats, Lunds universitet/Matematisk fysik; Lunds universitet/Fysiska institutionen

   Författare :Artis Mucenieks; [2023]
   Nyckelord :Physics and Astronomy;

   Sammanfattning : In this thesis we perform error analysis of a nuclear model based on density-functional theory developed in Lund. The Lund model allows us to perform calculations of nuclear spectra more efficiently by constructing a simple effective Hamiltonian reproducing the quadrupole deformation and pairing interaction strength parameters of a spherical Hartree-Fock reference functional. LÄS MER

3. 2. Electronic states in semiconductor double quantum dots and quantum rings - Theory and tight-binding modeling

   Master-uppsats, Lunds universitet/Fasta tillståndets fysik; Lunds universitet/Fysiska institutionen

   Författare :Calle Stenberg; [2021]
   Nyckelord :double quantum dots quantum rings tight-binding aharonov-bohm g-factor enhancement InAs; Physics and Astronomy;

   Sammanfattning : In recent experiments on semiconductor nanowires and quantum dots, enhanced g-factors up to several times the bulk value have been measured [1] [2]. The enhancement is attributed to orbital contributions g∗orb to the effective g-factor g∗ = g∗spin+g∗orb from the coupling of the high angular momentum ring-like states to the magnetic field. LÄS MER

4. 3. Best practice of extracting magnetocaloric properties in magnetic simulations

   Master-uppsats, Uppsala universitet/Materialteori

   Författare :Johan Bylin; [2019]
   Nyckelord :Magnetocaloric effect; Thermodynamics; Statistical mechanics; Monte Carlo simulations; Metropolis algorithm; Wang-Landau method; Isothermal change in entropy; Adiabatic change in temperature; Numerical methods; Effective spin models;

   Sammanfattning : In this thesis, a numerical study of simulating and computing the magnetocaloric properties of magnetic materials is presented. The main objective was to deduce the optimal procedure to obtain the isothermal change in entropy of magnetic systems, by evaluating two different formulas of entropy extraction, one relying on the magnetization of the material and the other on the magnet's heat capacity. LÄS MER

5. 4. A Space-Time Study of the Electron-Electron Interaction in High-TC Parent Compound La2CuO4: In Search of an Attractive Effective Interaction

   Master-uppsats, Lunds universitet/Matematisk fysik; Lunds universitet/Fysiska institutionen

   Författare :Tor Sjöstrand; [2016]
   Nyckelord :Physics and Astronomy;

   Sammanfattning : The superconductivity under doping in the famous cuprate compounds is believed to originate in the CuO2 planes. The mediator of pairing is generally accepted to be induced from electronic degrees of freedom. LÄS MER